1. Field of the Invention
Embodiments of the invention relate to an electrostatic capacity type touch screen panel and a method of manufacturing the same.
2. Discussion of the Related Art
Display devices such as a liquid crystal display, an electroluminescent display, and a plasma display panel have been recently spotlighted because of fast response time, low power consumption, and excellent color reproduction. The display devices have been used in various electronic products such as TVs, computer monitors, notebook computers, mobile phones, refrigerator displays, personal digital assistants, and automated teller machines. An interface between the display devices and a user is generally configured using various input devices such as keyboards, mouses, and digitizers. However, the user has to learn how to use the input device such as the keyboard and the mouse, and the input device occupies a separate space. Further, it is difficult to handle the display devices because of the input device. Thus, a demand for the simple and convenient input devices capable of reducing a malfunction has been increasing day by day. A touch screen panel, to which the user inputs information while directly contacting the screen of the display device with his or her finger or a pen, was proposed to meet the demand.
The touch screen panel is a simple input device capable of reducing the malfunction and can input information without using a separate input device. Further, because the user can easily operate the touch screen panel through the contents displayed on the screen of the touch screen panel, the touch screen panel has been applied to the various display devices.
The touch screen panel may be classified into a resistive type touch screen panel, a capacitive type touch screen panel, and an electromagnetic type touch screen panel based on a method for sensing a touched portion of the touch screen panel. The resistive type touch screen panel senses the touched portion by a voltage grade depending on a resistance in a state where a DC voltage is applied to a metal electrode formed on an upper substrate or a lower substrate of the resistive type touch screen panel. The capacitive type touch screen panel senses the touched portion by forming an equipotential surface on a conductive layer and sensing a voltage change location of upper and lower substrates of the capacitive type touch screen panel based on a touch operation. The electromagnetic type touch screen panel senses the touched portion by reading an LC value induced by touching a conductive layer with an electronic pen.
A related art electrostatic capacity type touch screen panel is described below with reference to FIGS. 1 and 2. FIG. 1 is a plane view of a related art electrostatic capacity type touch screen panel. FIG. 2 is a cross-sectional view taken along lines I-I′ and II-II′ of FIG. 1.
As shown in FIGS. 1 and 2, the related art electrostatic capacity type touch screen panel includes an electrode forming part 20, a routing wiring part 40, a pad part 60, and a protective layer 50.
The electrode forming part 20 is formed on a substrate 10. The electrode forming part 20 includes a plurality of first electrodes 21 arranged parallel to one another in a horizontal direction (for example, an X-axis direction) and a plurality of second electrodes 22 that are arranged to cross the plurality of first electrodes 21 in a vertical direction (for example, a Y-axis direction). The plurality of first electrodes 21 and the plurality of second electrodes 22 cross each other, but are electrically insulated from each other by an insulating layer 30. The adjacent first electrodes 21 are connected to each other using a connection electrode 41. The connection electrode 41 connects the adjacent first electrodes 21 to each other through contact holes 30a and 30b formed in the insulating layer 30 covering upper parts of the first and second electrodes 21 and 22.
The routing wiring part 40 is formed outside the electrode forming part 20. The routing wiring part 40 includes a plurality of first routing wires 42 respectively connected to the plurality of first electrodes 21 and a plurality of second routing wires 43 respectively connected to the plurality of second electrodes 22.
The pad part 60 includes a plurality of first pads 61 respectively connected to the plurality of first electrodes 21 through the plurality of first routing wires 42 and a plurality of second pads 62 respectively connected to the plurality of second electrodes 22 through the plurality of second routing wires 43.
The protective layer 50 covers the electrode forming part 20 and the routing wiring part 40 and prevents the first and second electrodes 21 and 22 and the first and second routing wires 42 and 43 from being exposed to the outside.
A method of manufacturing the related art electrostatic capacity type touch screen panel is described below with reference to FIGS. 3A to 3D.
As shown in FIG. 3A, a deposition process such as a sputtering process is performed on a substrate 10 including an electrode forming part, a routing wiring part, and a pad part to deposit a first conductive layer for forming first and second electrodes on the entire surface of the substrate 10. An indium-tin-oxide (ITO) layer is generally used as the first conductive layer. A photoresist is coated on the entire surface of the substrate 10 on which the first conductive layer is formed. A photolithography process using a first mask is then performed on the substrate 10 to form a first photoresist pattern exposing the first conductive layer on the electrode forming part. A wet etching process is performed on the first conductive layer exposed by the first photoresist pattern to remove the first conductive layer. An ashing process is then performed on the remaining first photoresist pattern to form a plurality of first electrodes 21 and a plurality of second electrodes 22 crossing the first electrodes 21 on the substrate 10.
As shown in FIG. 3B, a first insulating layer 30 is formed on the substrate 10 on which the plurality of first and second electrodes 21 and 22 are formed. A photolithography process using a second mask and an etching process are then performed to remove the first insulating layer 30 of the routing wiring part and the first insulating layer 30 of the pad part and to form first and second contact holes 30a and 30b passing through the first insulating layer 30 of the electrode forming part. The first and second contact holes 30a and 30b expose a portion of each of the first electrodes 21 adjacent to the first and second contact holes 30a and 30b. The first insulating layer 30 may be formed of silicon nitride, silicon oxide, or an organic resin, etc.
As shown in FIG. 3C, the deposition process such as the sputtering process is performed on the entire surface of the substrate 10, in which the first and second contact holes 30a and 30b are formed, to form a second conductive layer. The second conductive layer may be formed of aluminum (Al) or molybdenum (Mo). A photoresist is coated on the entire surface of the substrate 10 on which the second conductive layer is formed. A photolithography process using a third mask and an etching process are then performed to form on first and second routing wires 42 and 43 of the routing wiring part on the substrate 10 and to form connection electrodes 41 on the first insulating layer 30 of the electrode forming part. The connection electrodes 41 connect the first electrodes 21 which are separated each other through the first and second contact holes 30a and 30b formed in the first insulating layer 30.
As shown in FIG. 3D, a second insulating layer 50 as a protective layer is formed on the entire surface of the substrate 10 on which the connection electrodes 41 and the first and second routing wires 42 and 43 are formed. A photolithography process using a fourth mask and an etching process are then performed to form through holes 50a, 50b, and 50c passing through the second insulating layer 50. The through holes 50a, 50b, and 50c expose the first and second routing wires 42 and 43 of the routing wiring part.
However, as described above, the related art electrostatic capacity type touch screen panel is manufactured through the four mask processes, and each of the four mask processes involves the photolithography process requiring a series of successive processes including a coating process, an alignment process, an exposure process, a development process, a cleaning process, etc. Therefore, it is required to solve an increase in time and cost required in the four mask processes.